How to go about Bending this God forsaken 316l chainplate

[Eastward ho 24]

Made the rest of my chainplates with silicon bronze and boy do I love working with that stuff! Time constraints and lack of material I had to regrettably make my back stay out of 316l. it’s gonna have to go through my caprail and mount to the inside of the stern due to my placards ( nameplates.?) . I weld stainless pipes, and work with it quite often ( uaslly 308 or 410 or 309) I’m aware of heating it to much and cooking the chrome out and weakening it and causeing it to rust. To be honest as much ss I’ve welded cut and fabricated it, I’ve never had to bend it. So I’ve cut and drilled my piece and now I need to put maybe a 45 or 30 degree bend on it. Don’t have time to get it to a shop so I’m gonna clamp it down and beat it with a an 8 pound hammer.I've Got an acetylene speeed torch and a little map gas torch too. I’m worried it’s gonna crack if I just bend it. Has anyone bent. A piece or 3/8 316l flat bar it’s 2”x 3/8” by beating it? Should I put some heat on it? Or just beat it over?

[svninkasi]

Run by a local welding or machine shop. They will do it why you wait and probly for free.

[Reefmagnet]

Agree. Find someone with a press.

[Eastward ho 24]

I’m gonna try tommorrow but I don’t have much time mast is down clogging up the yard gotta get it up tommorrow to be a good neighbor. I’m leaving town so I’m kinda jammed up, so close just that little bend holding up the show. Or as I should have named my boat. “Nickel holding up a dollar”. If I can’t get a shop to help me it and I beat it over think it’s gonna crack? I took the sharp corners off it At the radius. I hate that 316 chain plate went through 80$ in 1/2” bits even going nice and slow with cutting oil. Hopefully when I get older I’ll get wiser and more patient

[Capt.Don]

Why don't you secure the mast with a halyard and get the chainplates made properly?

[Eastward ho 24]

Properly as in? Isn't whacking away at it curseing and screaming proper?

[a64pilot]

As you know SS comes in different heat treat levels, referred to as hardness, if it’s half hard or less, then it probably won’t crack, if half hard or more, it might.
Or worse, crack, but you not be able to see them.

[Dave_S]

Just bend it.

Hold the short end in the vice, place a close fit pipe over the other end and bend it in one smooth action and leave a good radius on the inside bend.

Drill the holes after bending. Use a pilot hole, don't let the drill stop drilling.

[DavidSaunders]

+1 to what Dave_S and A64pilot said. I suspect beating it will introduce a lot more random hard spots than one smooth bending action. Make sure the vise is really mounted well. Then if you even suspect a problem, then go ahead and follow the advice of Capt. Don above with a new piece. Good luck.

[Delancey]

A home brew press can be had by anyone with a car and a garage.

Use your car jack along with a length of timber to bridge the gap between the floor of the garage and the header supporting the open garage door.

[jimbunyard]

Originally Posted by Delancey

A home brew press can be had by anyone with a car and a garage.

Use your car jack along with a length of timber to bridge the gap between the floor of the garage and the header supporting the open garage door.

Yeah, but depending on how well your garage is built, trying to bend a 3/8" x 2" bar clamped between a jack/timber and the floor could also easily lift the header right off it's supporting structure...code is only as good as the guy driving (shooting?) the nails...

[Panope]

If you proceed with bending in a vice, use a piece of thick soft wood between the chainplate and vice jaws. The wood will crush, producing a softer radius bend.

For even better bend radius control, shape a piece of hardwood to whatever radius desired.

Steve

[Delancey]

Originally Posted by jimbunyard

Yeah, but depending on how well your garage is built, trying to bend a 3/8" x 2" bar clamped between a jack/timber and the floor could also easily lift the header right off it's supporting structure...code is only as good as the guy driving (shooting?) the nails...

Actually, what matters is the width (span) of the garage door, the depth front-to-back of the garage, whether or not there is a second story above the garage, the footings (or lack thereof) for the floor, and the size of the jack. How sloppy the guy who built it was has nothing to do with it.

If the OP wants to try the bending-in-a-vice trick I suggest he gets a long piece of pipe to slide over the end of the chainplate to use as a breaker bar.

[a64pilot]

Assuming it’s just 3/8” x 2”. I had a vise in the barn and an eight foot piece of pipe that I can assure you that I could easily bend it, as long as it’s not in the more than 1/2 hard condition.
I believe before attempting bending he needs to find that out.
Or take it to a good machine shop, they should be able to test the Rockwell hardness, and bend it also if it’s not too hard.

[jimbunyard]

Originally Posted by Delancey

Actually, what matters is the width (span) of the garage door, the depth front-to-back of the garage, whether or not there is a second story above the garage, the footings (or lack thereof) for the floor, and the size of the jack. How sloppy the guy who built it was has nothing to do with it.

If the OP wants to try the bending-in-a-vice trick I suggest he gets a long piece of pipe to slide over the end of the chainplate to use as a breaker bar.

My point is directed to people who may not have your expertise in designing makeshift vises; obviously, if the structure resisting the effort required to bend the plate has strength greater than the force required to bend it, there will be no problem.

It is very possible to lift the header off the studs in a standard American single story, 2 car garage with the with the force generated by bending a 3/8" x 2" steel bar, especially if the header is poorly or improperly fastened to its' supports. If it is well fastened, but say the bottom plate isn't, you could easily lift the whole shebang, header, roof and wall. If all is built as designed (i.e. to code) the garage door header trick should work, as should any doorway; in my 40+ years of building experience shoddy workmanship is quite a bit more common than superior, with good (or almost good) enough being the norm...

The main point is that there is a lot of force required, and that one should take care when improvising devices that exert tremendous forces.